The Hyperloop is said to go from one city to the other in less than half an hour, making better time than commercial airplanes flying between the two California cities. No announcement has been made on exactly how much Hyperloop would cost commuters, but Musk has previously said that it would be cheaper than today's airline and train tickets. He's also said that his project would be solar powered.

It seems like the stuff science fiction dreams are made of. But that's what was said about commercial space flight and electric cars, and both have done well for the ambitious jack of all trades, who has invested his own money to put a man on Mars within 15 years.

Even though Musk has proposed a design for Hyperloop, he does not plan to pursue the transportation system beyond that. "I don't have any plans to execute it, because I must remain focused on SpaceX and Tesla," he said, according to The Associated Press. "I think I kind of shot myself by ever mentioning the Hyperloop."

But just because Musk doesn't plan to pursue the technology doesn't mean he's not excited to talk about it. On a Google+ hangout last Thursday, Musk teased a little bit more information about the technology. He responded to a tweet that speculated that the Hyperloop would involve pneumatic tubes. "Your guess is the closest I've seen anyone guess so far," he said.